采用等初末温度比较法和等温法分别在微波及水浴加热下反应结晶合成了碱式碳酸镁颗粒.用扫描电镜(SEM)、X射线衍射(XRD)以及粒度分析表征不同阶段样品的晶体结构、表面形貌和粒度分布,用化学分析(滴定法)跟踪反应结晶过程中镁离子浓度的变化.实验结果表明:所得晶体由纳米片自组装而成,微波场对碳酸镁结晶具有促进作用,即微波对碳酸镁结晶中初级纳米颗粒的组装具有促进作用,可提高碱式碳酸镁的生长速率,增大颗粒粒度,但没有改变产物晶习;不同温度下碱式碳酸镁转变路径不同,较高温度时无定形颗粒直接组装成碱式碳酸镁,较低温度时将出现正碳酸镁中间态,经由不同相转变历程的碱式碳酸镁纳米片微观形貌和组装方式并不相同.%Same initial and final temperature comparative method and isothermal method were chosen to synthesize hydromagnesite particles under microwave irritation and water bath heating. SEM,XRD,and CSD were used to characterize crystal structure, surface morphology, and particle size distribution of the samples at different stages. Chemical titration analysis was used to track the change of magnesium ion concentration in crystallization process. Experimental results showed that hydromagnesite crystals were constructed of lots of self-assembled nano-sheets. Microwave accelerated the crystallization of magnesium carbonate,that is to say microwave could accelerate the assembly of primary nano-particles in magnesium carbonate crystallization,thus enhanced the growth rate of hydromagnesite and then increased the crystal size,but did not change the crystal habit; transition paths of hydromagnesite at different temperatures were different, the amorphous substance assembled into hydromagnesite at higher temperature and nesquehonite intermediate would appear at lower temperature, and the micro-morphology and assemble manner of hydrom agnesite nano-sheets by different phase-transfer processes were not the same.
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